In a 2-quart (8-cup) ovenproof pot or Dutch oven, arrange layers of salt pork, salmon, onions, potatoes, and herbs. Season and cover with rolled out dough. Make an incision in the dough. Pour beer though the incision, filling up the pastry shell. Cook covered at 200°F for 3.5 hours. Remove cover and return to oven for an additional hour or until crust turns golden.